ArduCopter 2.8 / 2.8.1 released

Arducopter 2.8.1 is now in the mission planner and in the downloads area! Remember to do your MP configuration again after loading this code, since it erases your EEPROM and sets it to the new defaults. 

Note: Issues with APM1 user's level feature not working are now resolved.  If you installed 2.8 we highly recommend you upgrade to 2.8.1 as 430 extra bytes of RAM have been freed up which reduces the chance of memory corruption (although we haven't seen any cases of this on the APM2 at least) .

Note #2: this release has not gone out for Traditional Helicopters until they can be tested fully.  Flip and Toy mode have also not been fully tested.

Improvements over 2.7.3:

  • Improved ACRO mode (Leonard Hall)
  • Improved stability patch to reduce "climb-on-yaw" problem (Leonard, Rob Lefebvre, Randy)
  • Rate controller targets moved to body frames (yaw control now works properly when copter is inverted) (Leonard/Randy)
  • Less bouncy Stabilize yaw control (Leonard)
  • OpticalFlow sensor support for APM2.5 (Randy)
  • DMP works again by adding "#define DMP_ENABLED ENABLED" to APM_Config.h You can also log DMP vs DCM to the dataflash by adding "#define SECONDARY_DMP_ENABLED ENABLED" (Randy)
  • Watch dog added to shutdown motors if main loop feezes for 2 seconds (Randy)
  • Thrust curve added to linearize pwm->thrust. Removes deadzone found above 90% throttle in most ESC/motors (Randy)
  • More timing improvements (main loop is now tied to MPU6000s interrupt) (Randy)
  • GPS NMEA bug fix (Alexey Kozin)
  • Logging improvements (log I terms, dump all settings at head of dataflash log) (Jason)


Bug Fixes / Parameter changes:

  • fixed skipping of last waypoint (Jason)
  • resolved twitching when no GPS attached (Tridge)
  • fixed loss of altitude if alt hold is engaged before first GPS lock (Randy/Jason)
  • moved Roll-Pitch I terms from Stabilize controllers to Rate controllers
  • TILT_COMPENSATION param tuned for TradHeli (Rob)

Code Cleanup:

  • HAL changes for platform portability (Pat Hickey)
  • Removed INSTANT_PWM (Randy)

As per usual PIDs are optimised for the 3DR/jDrones quad with 850 motors and 10" props. If you're using more powerful motors/props and are seeing bad flight behaviour in stabilize, start by turning down Rate Roll P in 25% steps.

Please note that on this release we've moved the Roll and Pitch I terms from the Stabilize controller to the Rate controller. There's some evidence that says this can lead to flips on take-off if you move the roll or pitch sticks around as you take-off so we recommend you leave these sticks in the middle until you're in the air.

Please feel free to report issues you find in the discussion below and/or add them to the issues list.

Thanks and enjoy!

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  • I am struggling with the 2.9r1 and also r2 for the last days.

    I have a H-Quad with an APM2.5 and have huge problems with the alt hold. When I siwtch to alt hold, it starts oszilating and jumping and wobbling. No matter what PID values I change I never get a good alt hold.

    Yesterday I enabled the sonar by adding the two defines to the config, but sonar seems not to be used.

    After many tries, I wanted to see, if something is wrong with my hardware and so I installed 2.6. Then alt hold worked fine. Sonar was working too. I could park the copter in 2m hight, walk under it and it was pushed up by the sonar.

    Only downside of the switch to the 2.6 was that it costs me 2 props, when I switched to RTL. The copter did not climb and come home. He dropped down to the ground and bounced of to flip over to the back.

    The strange thing ist, that I have a Y6 copter with APM2 and there the 2.9 works really fine. There I go with all PIDs at default values and it works greate except some small oszilations, that could be eliminated with PID tuning.

    My H-Quad is not as rigid as the y6. Maybe that could cause the problems, but when I fly it in stabilize it flies really well. No wobbling but very stable.

    Im uploading some videos showing the problems. When uploads are ready, I could post the links.

  • Developer

    ArduCopter 2.9-rc2 (release candidate #2) is now in the downloads area.


    Improvements over 2.9-rc1:
    1) APM1 fix so it works with inertial nav (5hz update rate of baro was beyond the tolerance set in the inav library)
    2) increased throttle rate gains from 1.0 to 6.0, alt hold gains from 1.0 to 2.0


    You can also see the full list of improvements over 2.8.1 in the description that appears in the downloads area or you can checkout the ReleaseNotes.txt in the actual zip itself.

  • Just flew v2.9.1 on my disco and it's really good.  Love the new alt hold. 

    Auto-trim did not work for me. I was completely sideways.  So i just manually tweaked the AHRS parameters to make it level. Seemed to work

  • i try indoor test for 2.9 rc1

    my gps module get lock but hdop is high and position changes quickly

    in this firmware ahrs_gps_gain =1 

    this bad for indor fly

  • Randy

        I have a problem about GPS Module MTEK 3329. When i'll test loiter is sometime gps is not update position and drone move slide very far (Update GPS Firmware 1.9). pls check is problem.

    Thank you , Balloon 

  • Randy

    I like the feature of automatic landing.

    However, some strange observation of auto landing that is instead of decent my quad is tend to lift.

    Actually, first auto landing is very smooth and quietly land. After this process, I fly my quad again and tried auto landing in second atempt. At the moment of switch, quad is going up. 

    I setup my quad becomes moderate that is equipped 10 inch propeller and 3S LiPo.

  • This may already be common knowledge...but here goes...


    On my new APM 2.5, there's a bunch of dedicated LED connectors.

    I also see the JDrone LED controller board is available for driving lights.


    1) Can an LED strip be powered directly from APM 2.5 now?  Or are there still power limitations?

    2) The JDrones LED controller still required for LED strips?

    3) Does special code need to be compiled for LEDs, or is this now standard?




  • Hi all,

    We have faced a problem during new accelerometer calibration method using APM1 with 2.9-rc1 and APM planner 1.2.27. Is there anybody having the same problem?

    When we clicked beta calibration button on APM planner it is saying us to level arducopter and press any key. We are making so and pressing a key/the button. But it is not proceeding to second step in which we will be requested to turn the quad left as we see in Randy's video. After that when we clicked the disconnect button we are getting a message saying "Serial connection lost". We are attaching APM log file.

    All the best.



  • Randy,

        I just upload 2.9.1 rc1. I connect APM Planner but it have lag on HUD when i rotate my drone. Check please.


  • Developer

    FYI - we found an issue with the inertial nav for the APM1.  It's fixed in trunk so I'll push out another release candidate in the next 24hours or so.

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